摘要
采用光学显微镜、扫描电镜、电子万能拉伸试验机测试分析手段,研究硅含量对耐热球墨铸铁显微组织和室温、高温力学性能的影响规律。试验结果表明,随着硅含量的增加,石墨圆整度逐渐下降,硅含量(质量分数,下同)达到3.8%时,基体中开始出现碎块状石墨,球化级别为3级。随着硅含量从2.8%增加至4.8%,珠光体含量从51.06%减少至8.65%。随着硅含量的增加,室温抗拉强度先上升后下降,伸长率逐渐下降,当硅含量为3.8%时,抗拉强度为726 MPa,伸长率为1.6%。随着硅含量的增加,高温抗拉强度逐渐上升,伸长率逐渐下降,当硅含量为4.8%时,抗拉强度为532 MPa,伸长率为6%。室温拉伸断口出现大量的解理面和河流花样,表现形式为脆性断裂。高温拉伸断口出现韧窝和撕裂棱,拉伸断口表现形式为韧-脆混合型断裂。
The influence of silicon content on microstructure and mechanical properties of heat-resistant nodular cast iron at room temperature and high temperature was studied by means of optical microscope,scanning electron microscope and electronic universal tensile testing machine.The test results show that with the increase of silicon content,the roundness of graphite gradually decreases.When the silicon content(mass fraction,similarly hereinafter)reaches 3.8%,fragmented graphite begins to appear in the matrix,and the spheroidization grade is grade 3.As the silicon content increases from 2.8%to 4.8%,the pearlite content decreases from 51.06%to 8.65%.With the increase of silicon content,the room temperature tensile strength first increases and then decreases,and the elongation decreases gradually.When the silicon content is 3.8%,the tensile strength is 726 MPa and the elongation is 1.6%.With the increase of silicon content,the high temperature tensile strength gradually increases and the elongation decreases gradually.When the silicon content is 4.8%,the tensile strength is 532 MPa and the elongation is 6%.A large number of cleavage planes and river patterns appear in the tensile fracture at room temperature,and the form is brittle fracture.Dimples and tear edges appear in the high temperature tensile fracture,and the tensile fracture form is ductile-brittle mixed fracture.
作者
赵竞
王丽萍
冯义成
姜文勇
王雷
郭二军
Zhao Jing;Wang Liping;Feng Yicheng;Jiang Wenyong;Wang Lei;Guo Erjun(School of Material Science and Chemical Engineering,Harbin University of science and Technology,Harbin Heilongjiang 150040,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2022年第9期227-233,共7页
Heat Treatment of Metals
基金
国家自然科学基金(51674094)。
关键词
耐热球墨铸铁
显微组织
室温性能
高温性能
断口形貌
heat-resistant nodular cast iron
microstructure
room-temperature properties
high-temperature properties
fracture morphology